1. Field of the Invention
The present invention relates to a novel machining and assembling apparatus and, more particularly, to a novel machining and assembling apparatus which allows flexibly for changes in the machining or assembling setup following a modification in the production line configuration, thereby reducing the down time that occurs between such changes.
2. Description of the Prior Art
The trends in recent years for multiple-item, small-lot production have given rise to a production method whereby a single production line carries a plurality of workpieces or part feeding pallets simultaneously for machining or assembling.
In such a setup, the production line is partitioned into a plurality of suitable production units. Each production unit utilizes at least one general-purpose robot to accomplish the task assigned thereto. This makes it possible to allow for not-too-significant changes in the workpiece machining or part assembling procedure.
However, once a production unit configuration is decided on the production line, the configuration itself is difficult to modify. Where a significant change is required of the workpiece, there is no choice but to initiate a major effort to modify the production unit configuration constituting the production line so as to accommodate that change.
Specifically, as shown in FIG. 9, reference character a represents a single assembling and machining line. Reference characters A, B and C are production units each having a robot.
A workpiece b flows on the line a through the units A, B and C, in that order. After completion of the treatment in each production unit, the workpiece b is taken out to a delivery position c.
If a change in the workpiece requires rearranging the units into A, C and B for production in that order, the conventional approach is to have the units B and C switch their places. That is, a differently arranged production line d needs to be re-established, as shown in FIG. 10.
Such rearrangement of the production line setup takes considerable time; it most often takes more than half a production day. Multiple-item small-lot production generally calls for such setup changes frequently. As a result, the plant having this type of production line often suffers significantly in productivity.